The present invention relates to floor treating apparatus and more particularly to apparatus which scrubs a floor and removes the wet soilage from the floor in a single pass.
Various forms of floor treating machines are presently available which scrub a floor surface with a cleaning solution and remove the wet soilage from the floor. Such machines, if self propelled, are referred to as automatic floor scrubbers and typically include a brush head supporting one or more vertical axis brushes, a squeegee assembly which collects the wet soilage or dirty solution and a vacuum system which will pick up and remove the wet solution after the scrubbing operation. Such machines generally require only a single person for operation and may clean floor surfaces at 30,000 square feet per hour. A cleaning solution is automatically metered to the brush head from a solution tank. The vacuum system typically includes a blower having an inlet connected to the squeegee assembly through a recovery tank. The blower sucks up the wet soilage and deposits it in the recovery tank.
Examples of such prior machines of the general type just described may be found in U.S. Pat. No. 2,680,260 entitled SCRUBBING MACHINE WITH ROTATING BRUSH FOR SCRUBBING SURFACES and issued on June 8, 1954, to Danielsson et al; U.S. Pat. No. 2,978,719 entitled MOBILE FLOOR TREATING MACHINE and issued on April 11, 1961, to Arones; U.S. Pat. No. 3,277,511 entitled ADJUSTABLE WIDTH FLOOR TREATING MACHINE and issued on Oct. 11, 1966, to Little et al; U.S. Pat. No. 3,408,673 entitled FLOOR SCRUBBING MACHINE and issued on Nov. 5, 1968, to Oxel; U.S. Pat. No. 3,550,181 entitled APPARATUS FOR CLEANING FLOORS and issued on Dec. 29, 1970, to Dolan et al; U.S. Pat. No. 3,866,541 entitled SELF-PROPELLED FLOOR CLEANING APPARATUS WITH REMOVABLE BRUSH and issued on Feb. 18, 1975, to O'Connor et al; and U.S. Pat. No. 4,006,506 entitled SURFACE CLEANING MACHINE WITH SQUEEGEE ASSEMBLY and issued on Feb. 8, 1977, to Burgoon.
The prior floor scrubbing machines, whether manually or self propelled, have generally used separate, independent tanks for the cleaning solution and for storing the recovered dirty solution. The separate tanks are usually mounted side by side or in a front-to-back relationship. This mounting results in a shifting of the center of gravity of the machine during operation. This shifting is caused by transfer of the fluid from one tank to another and may have an adverse effect on machine operation. The changing center of gravity requires a four point support for the machine, that is, four floor surface engaging wheels must be used to ensure stable operation of the machine.
It has been proposed to mount the cleaning solution tank and the recovery tank in a top-to-bottom or one above the other relationship. Such arrangement may be acceptable in small, low capacity, manually propelled scrubbing machines such as illustrated in the aforementioned U.S. Patent to Dolan et al No. 3,550,181. With such an arrangement, the center of gravity of the scrubber will be raised or lowered during operation without a front-to-back or lateral shift. Top heaviness and resulting instability may become a problem.
When a one-on-top of the other tank arrangement is employed in a self-propelled floor treating machine, significant problems are experienced with proper location and sizing of the tanks and with stabilizing the machine to counteract top heaviness. Typically, the top-to-bottom tank arrangement is not adaptable to a battery powered, self-propelled floor scrubber since insufficient space is left to mount the batteries. U.S. Pat. No. 3,866,541 discloses an automatic scrubber with the recovery and solution tanks in a vertical relationship. This machine, however, employs an internal combustion engine driving a hydraulic pump and hydraulic motors to propel the apparatus. An internal combustion engine is unacceptable in most indoor environments within which a floor scrubber finds its primary utility.